How does this gear pattern look? (1 Viewer)

[Monty231]

Installing ARB lockers and a new Nitro 4.10 ring and pinion. I have gone from .020 to .005 pinion shim and the pattern doesn't seem to change. I've also experimented with the backlash trying to keep it between .006 and .010, how just to see how the pattern changed I took a pattern at .020 backlash. It all looks the same. That being said this is set a .010 pinion shim with .010 backlash.

What are yalls thoughts?

 

[RustyNailJustin]

The pattern is to deep but your above comments make me wonder why you are not seeing a different patterns. What is your experience in setting up R&P? Just want to make sure my terminology and yours match up.
I will say I have set up a ton of gears and I have never had a pattern that won't change

 

[pjohnson]

The two pictures show different patterns to me, but I have never set up gears before.

 

[shaneus]

Never set up a landcruiser diff. Have set up several 9" ford rears (probably the easiest). I agree with Rusty nail above that the pinion looks to deep in your photos. You know you are looking for a nice wide smear centered on the pressure side of the ring. Make sure pinion is torqued and has good pre load on taper bearings (on a ford this is measured as so many inch pounds just to turn pinion). Once pinion is about right front to back, then work on carrier left and right - (I aint done a cruiser - not sure if this is with shims or with adjuster nuts like on a 9" ford).

Either way, there is no "snug up and check", gotta torque all bolts and re coat with white lead or whatever you kids are using these days.

 

[shawnfj40]

Follow the FSM and you can't go wrong. The second pic is of your "coast" contact. try to not worry about that one very much. The one you need to focus on is the drive side. If follow the FSM (its basically what shane us said above) changing shims will change your pinion contact for sure. It can be a pain but how ever many times it takes to get it right is worth it in the long run.

 

[B y r o n]

When I rebuilt my 3rd members with ARB's and new gears I contacted Zuk. He was very helpful and was a great help in getting the shim thickness sorted with regard to the pattern.

 

[Monty231]

Thanks for the replies. I called JTs, where I got the gears and got everything sorted out.

 

[RustyNailJustin]

Thanks for the replies. I called JTs, where I got the gears and got everything sorted out.

Post up your final pattern pics and your numbers.

 

[shawnfj40]

Never set up a landcruiser diff. Have set up several 9" ford rears (probably the easiest). I agree with Rusty nail above that the pinion looks to deep in your photos. You know you are looking for a nice wide smear centered on the pressure side of the ring. Make sure pinion is torqued and has good pre load on taper bearings (on a ford this is measured as so many inch pounds just to turn pinion). Once pinion is about right front to back, then work on carrier left and right - (I aint done a cruiser - not sure if this is with shims or with adjuster nuts like on a 9" ford).

Either way, there is no "snug up and check", gotta torque all bolts and re coat with white lead or whatever you kids are using these days.

The bearing preload and backlash are done with adjusters on Landcruiser axles.

 

[Monty231]

So, in my haste to get everything back together, before had to go out of town, I did not get pictures. It is back together and I've driven it a few miles. First drive was great no noise. Since, then it has gotten a whine at very light throttle. I will say with a three speed tcase, loud exhaust and M/Ts hearing anything is a challenge in the 40.

Leading up to this install I have read and reread as much info as I could get my hands on, looked at patterns on many different sites. One thing I read was get the pattern set root to face and don't worry about the heel to toe placement of the pattern if it wouldn't move, so I convinced myself it was good. Now, I'm thinking I screwed up and need to pull it back apart and figure out where I have gone wrong. One thought I had is maybe some trash got under the pinion bearing when I pressed it on. Another thought I had was the bearing itself. It is a Koyo from a Sierra install kit, NSK bearings came out, is it possible the Koyo has a different spec? I'm at a loss and feel like an idiot.

 

[want2wheel]

Koyo are good bearings. I would pull the cover and check the pattern on the gear before you do anything else.

 

[shawnfj40]

It does matter if the pattern is off in either direction. It will move (it doesn't have a choice). If your pinion depth changes, so does the contact area.

 

[shaneus]

I'm sure nitro gave break in instructions. The last set of Richmond gears I used came with a long list of break in instructions. Like 5 minutes no load on jack stands, 5 minutes around the neighborhood slow, then longer use all while stopping and checking the housing for heat.

I would drive again and feel for heat on the housing around the pinion. If things are not right its gonna get hot. If hot it needs opened up and looked at again. Maybe compare with other known good vehicle to calibrate your hand for normal temp to whatever your cruiser temp is.

Hopefully things are good inside.

 

[Trollhole]

10-20 min at 45mph. I do 5 cycles in between cooling. Pinion is too deep in the first pic and too far on on the second.

 

[Cruiserdrew]

I'd pull it out and apart before the pattern is set. If it's whining, you have a problem. You have a lot of cash in ARBs, gears and bearings, don't mess it up. But as you say, are you sure it's the differential that's whining?

We need some more info too. What is your backlash, your final painted drive pattern and pinion/carrier preloads?

Break in-everyone has a different idea:

My conservative break in procedure: (AutoZone 80W-90 in 5 gallon pail-cheap and suitable)
Drive under 5 miles of normal city low speed traffic and park.
Then normal city traffic, short trips and no freeway for 100 miles. On (light)and off throttle as much as possible
At 100 miles, drain and fill diff oil-looking for problems-metal, dark oil etc.
Drive another 400 miles of mixed traffic, with no long freeway over 20 miles.
After 500 total, swap to the good gear oil and consider the break in done.

 

[Monty231]

So, as far as break in goes I have 80-90 store brand gear oil from Oreillys. I have three drives totaling 15 miles, no faster than 40mph.

Pinion preload was 15 in/lb with a solid spacer
Backlash is .007
I kept the .010 pinion shim. I convinced myself it was ok after reading the Yukon install guide online and a PDF with a excerpt from a book from Randy's ring and pinion. Both said don't worry about heel toe pattern just face root pattern.
Carrier preload is a guesstimate. I tightened it incrementally with my homemade spanner wrench till it felt tight enough. The drag on the pinion was 20 in/lbs with carrier preload.

I really appreciate the replies from everyone. Thank for your help, I know I will figure this out eventually even if it costs me more in the long run then sending them out. It's a skill I've wanted to learn for a while.

 

[Monty231]

Alright men, progress! I pulled the diff this afternoon and focused on the big pinion bearing. Notice any difference?

The one on the left is a Koyo ST4090, the one on the right is a Koyo 30308. Per what I found online the 30308 is .25mm thicker than the ST4090. I think I found the problem. Thanks again for the help! I'm gonna put I back together with this old bearing and take a pattern. I'll post up a pattern later.

 

[pb4ugo]

Are you changing the races too? It looks like their taper is different.

 

[Monty231]

Are you changing the races too? It looks like their taper is different.

Yes, I definitely will be changing races, they have totally different angles on them.

 

[Cruiserdrew]

I sort of feel you are going about this wrong. Use the right bearing, set the pinion depth correctly, then set pinion pre-load, then set backlash and carrier pre-load. You really can't use a pinion shim that almost works. It's a pretty exact science.

I do applaud you for doing this on your own, because it means you understand the process, and have bought all the special tooling to do it correctly.

But it's a re-iterative process. Apart and back together maybe 6-10 times to get it right. No way to fake it.